The invention relates to a motor vehicle door latch, comprising a locking mechanism, an electric drive, a locking unit and a coupling lever, said coupling lever acting on the locking unit and in which the coupling lever can be actuated by the electric drive counter to the force of a spring, in particular a center-off spring.
A motor vehicle door latch contains in most cases a catch and a pawl with the pawl being able to stop the rotation of the catch. When the pawl is lifted off the catch, the locking mechanism is opened. This releases a previously retained locking bolt. In the closed state of the locking mechanism, the catch is pretensioned by the sealing pressure of the door seal and also contains a spring, acting on the catch in the direction of its opening position. The locking unit can be a central locking unit or a central locking unit combined with an electric opening or anti-theft lock or child-lock.
A locking unit, in particular a central locking unit, ensures that in its “locked” position, an associated actuating lever, for instance, an external actuating lever, is not operational. In this position, the locking mechanism cannot be opened by the external actuating lever. In contrast, the locking unit can be moved from a “locked” into an “unlocked” position, in most cases by means of an internal actuating lever so that, for instance, even with the motor vehicle door latch in the locked position, persons inside the motor vehicle are able to open the door from the inside. On the other hand, an anti-theft mechanism generally ensures that also the internal actuating lever remains without function in the position “anti-theft lock on”. This means that in the position “anti-theft lock on”, a motor vehicle door containing the motor vehicle door latch can neither be opened from the outside nor from the inside. The door can also not be unlocked from inside, using the internal actuating lever.
DE 10 2010 035 083 A1 discloses a motor vehicle door latch in which two latch functions are provided by a single drive, with the actuator that can be acted upon, containing a control contour. To reach the control contour very precise movement is required with very little play.